Should anyone have any thing on this system, they would need you to either add your e-mail to your profile, or send them an e-mail.
Referring to the dwell, are you sure the manual says "should be set" or does it say "should read"? In this case dwell is the % of on time the pulse happens for the fuel valve, which will/should vary with all sorts of information, as it is the thing that gets changed in "closed loop" running, and the timing is a pretty straight forward vac advance the same as 4g6* motors had been using since the early 80s.
The MIL light will come on if they let the truck idle for more than about 4 min, and as far as I know, the "solution" is to tell the operator to not leave it running and not driving for more than a couple of minutes.
The K in the model number does not indicate the drive by wire models, I know the emissions system from the 'D' in the serial number series.
Have you checked the timing with a timing light?, and checked to see that the vac advance really is working? I have had a few where the port inside the throttle body for the vac advance was plugged up, and cleaning with a very small welding tip cleaner was a good fix. my bet from your description is either the distributor vac advance hose in the wrong spot on the throttle body or a stuck weight on the advance plate, or too long a screw in the dist. catching the pickup plate keeping it from moving. It may also be related to where the pickup for the computer's temp sensor is located, if you add something as thick as an extra nut you will change the reading considerably, I know even an added flat washer will change what temp the computer sees by about 5 degrees..